Lens blocking device



Jan. 1, 1952 D. P. BERNHEIM x-TAL 2,530,507

LENS BLOCKING DEVICE Filed Jan. 12, 1948 4 Sheets-Sheet l Fig, 1 6 F FI04 I22 INVENTOR. DANIEL P. iBERNHElM CARL G. VF RBERG ATTORNEY Jan. 1,1952 D. P. BERNHEIM EI'AL 7 LENS BLOCKING DEVICE 4 Sheets-Sheet 2 FiledJan. 12, 1948 G a E NRE R E v V m m s T A a L m: R 4 l N W I mm all,

1952 D. P, BERNHEIM ETAL 2,

LENS BLOCKING DEVICE 4 Sheets-Sheet 4 Filed Jan. 12, 1948 INVENTOR.DANIEL P. BERNHEIM CARL e sum/E4; rseks AT TO N EV Patented Jan. 1,1.952

UNITED PATENT OFFICE thivs'ixiizzi i n zibnvicn w-Dimielm. FBeniheim,soutsfiriage, ant oan a. {Silverherg, iStnrbridge, .i Ma'ssi, hasigndrsto A merican Optical mpany;

Mass qafvoluntary. association mrbMassachusetts -ixiasm=ation Jaiiiiaiy12, 1948; si ia'liitofiii'ir i invention relates to improvements --in-blooking devicesan'd has particular reference to improved means :andmethod of blocking lenses.

One of the principal objectsgof thewinvention is to provide improved.meansand method of blocking semis-finished lens blanks whereby thepositional "factors of the finished prescriptive power which; theIGHSriSvt/O possess may "be located prior to thewblocking and the saidt-lens biank blocked-while he1d-in -said located position.

Another object of the invention is to ,prov-ide improved means andmethod of blocking tlenses whereby the; prism and hrcylinder axesandextent of zsaidtprism -may be located priorttoiblceking the seniifinished lens blank and 1 the said alens blank blocked while held saidposition.

Another object is to provide; in proved sighting and gripping means/forsemi-finished.lenslolanks whereby .the optical characteristics which.the finished lens is to possess mayhetpredetermined and the said lensblank held 'byfsaidl rilaping means in'siijch amann'er as to re taintits,{oosition with respect to its wpresc'riijtive characteristics, wherebyit may be transferred bytaslight vertical movement into alignmntwith and.bie: secured to a lens block While held in posit on.

Anothei' object is 'the prov'isio'n of a movable heating'elementposinoned "for insertion. between atlens blank and a lens blockto "siiniiltaiieously heat the adjacent surfaces thereof-beforesecuringthe blank to the block.

. Another object is to lbrovi'de novel Ime'a'nsantl method 0T appiym'ant'adhesijve'to'the adjoining surfaces of 'fa'ien'sblank and a lensbiockior Another object is the provisie at an improved adhesive inthenature of ashlidffinit for ,securi'n'g a lens blank "to a lens blockarid method of making the same. A

Another object isto p eviue a-nev'i'e having means ror suppernng-alens'blahk, me ns for gripping means vertically movgenie-ancient ofadjacent relation with the iens la l'ahk and adapted to'positio'n saidlens blank witnrespeet to: saidle'n's block. v v

Another object is to firov ide a-fltfice Having means for positioning alens hlank wi hiesfibt to the prescriptive characteristics it the ishedle'nsis to possess; rheans for gnppiiig ahd moving the lens blankvertically :xvhile held in said position, and means: for returning: the:btanl':

and attaching said blank ttoiallens block atrsub' stantiallythesame-ggenei a'l location whereii'tzwas originally positioned t g-iinped ta-nan "on line '1 taming the-s The'invention also consists of newan orig- --iiial "featnres oficbnstruction and combination-6f ip'arts"hereinafter set idi' th and maimed. A1- tli'rough :the novel featuresware 'show-'n and dei sdrib'ed and are 5pointed o'utfin "the claims, theipresen t invention .iwill 'b'e more-clearly understood wand theadvantages thereof fully realized from :th fioliowing description readin conjunction Wibh the accompanying drawings, which:

jFig- 1 1 is :a front nelevat-ional View "of a device uembodyingtheginventiont rFig,:2:-is-a""longitudinal-{sectionalwiewtakencnlinemP-t-z :of Fig. L1 showing the. sighting: and grip"- ping; means foraligning alllens blank;

is a ,plan view of said *device partly .in

.sectionwitnthesightingrmeans-memoved toisnow n ting table;

.rigniis'a se'nonai view s'howingt details of the construction oftthelens block with alents blank attached-thereto;

"Fig.8 ascnbnai new sho'wingtne means-for locating len's supportin'p'in-"in the I prism adjustns'edas the a hesive for securin a lensblank qh i sb k: t j

Fig. .10 is a sectional view or the "pitch tenet Fig; 11; is a viewsimilar to Fig. .agsn'owing fa frjnodifiedtype bf-nearing element andmounting merger nep rtmg bracket and illustrating pnngdet ritnie-enamsmfor reed positiin'i.

Wh'enwblocking a -l'ens for the naming of the rena final prescriptivesurface on said lensitis-o f nextreme importance warmest-1a iens flo-.;ca'ted: tn properly centered nos ion andin invia-15o 'ofcextremeirhp'ortafihe that the-axis bf the i 3 ridian and that the power thereofbe accurately controlled.

An important feature of the present invention, therefore, is theprovision of improved means and method whereby all of the positional andprescriptive characteristics which the resultant lens is to possess maybe accurately determined prior to thefinal securing of the lens blank tothe lens block so that the said lens blank will be held in properposition in the abrading machine employed to complete the finalprescriptive surface on said blank.

A unique feature of the present device and method is that it eliminatesall guesswork and insures that the accurate optical characteristics arebeing introduced during the final abrading of the prescriptive surfaceon the lens blank.

Although means and methods have been em-' ployed in the past fordetermining all the prescriptive components of a lens prior to the finalpositioning of the lens blank with respect to the lens block, it hasbeen very difiicult to provide suitable means for efiiciently securingthe lens blank to the lens block. One of the most satisfactory prior artdevices was thetype employing a pitch pot or kettle supported forpositioning in alignment with the lens block to permit the flow ofmolten pitch from the kettle onto said lens block, the pitch having beenpreviously rendered molten by heating means associated with the kettle.This process is, however, slow and messy and requires excessive handlingof the lens blank by parts of the machine required to transfer the lensblank from sighting position to another section of the machine forsecurement to the lens 7 block. This extra movement introduces anadditional disadvantageous factor in that there is a possibility thatthe lens blank may be accidentally shifted from its position asinitially located during the transfer to the'lens block and thus beconsequently inaccurately finished.

The present invention improves upon prior art devices by providing aremovable table for locating the lens blank adjacent the sighting means,the table being provided with improved means for positioning the lensblank with respect to the amount of prism to be provided, and providingmeans for positioning a heating element between the lens blank and thelens block to which the blank is to be secured to heat the adjacentsurfaces of the blank and the block simultaneously before application ofan adhesive in the nature of a solid, whereby the lens blank will befixedly secured to the lens block. With this construction there is alsoprovided means for raising the lens blank vertically from the table andlowering the blank into contacting position with the lens block, theentire line of movement of the lens blank being always in a directionperpendicular to the surface of the lens blank supporting table.

This eliminates excessive movement of the lens blank after beingpositioned by the sighting device, and also eliminates the use of akettle carrying a liquid adhesive, together with the accessoriesnecessary for confining the liquid adhesive to the desired surfaces tobe adhered, consequently resulting in an accurate positioning of thelens blank upon the lens block in a neat and eflicient manner.

Referring more particularly to the drawings wherein like characters ofreference designate like parts throughout the several views, the deviceembodying the invention comprises a hollow base I having spaced paralleltransverse supports 2 and 3 thereon. Extending upwardly adjacent 4. therear ends of the supports 2 and 3 is a hollow upright 4 having a web 5in the upper portion thereof adapted to carry a forwardly and upwardlyextending supporting bracket 6, the bracket being fixedly secured to theweb 5 by means such as screws or bolts 1.

Located in spanning relation to the forward portions of the spacedsupports 2 and 3 is a movable table 8 provided on the underside thereofwith a plurality of removable metal pads 9 (Figs. 2 and 6), each ofwhich pads is adapted to make end to end contact with a correspondingaligned removable metal pad If], the pads I0 being located in the uppersurfaces of the supports 2 and 3 and in the upper surface of aprotruding portion II of'the front wall of the upright 4. The adjoiningsurfaces of the pads 9 and III are machined so that the upper surface ofthe table 8 will be located in a perfectly horizontal plane, it beingpossible to adjust this plane by grinding the ends of one or more of thepads 9 and I0. Locking pins I2 are fixedly located in the upper surfacesof the supports 2 and 3 and are adapted to removably engage bushings I3located in the under side of the table 8, and serve to hold the tablestationary. The table 8, supports 2 and 3, and upright portion II areprovided with vertical openings I4 concentric with the inner ends ofpads 9 and I0 and bushings I3 so that they may be easily knocked out forrepair or replacement if desired.

Manually operative means is provided for moving the table 8 and includesa vertical shaft I5 rotatably mounted throughout the major portion ofits length in a fixed bushing I1 in the support 3 and having its upperend fixedly secured near the right rear corner of the tablet and held insaid fixed position by a set screw IE or the like.

Spaced bushings I8 are fixedly located in the front and rear ends of thesupport 3 and serve to rotatably support a transverse shaft IS, theforward end of which carries a hub 20 secured thereon by a pin 2|, therear end of shaft I9 having a washer 22 secured thereon by a pin 23 forretaining the shaft I9 in position. A handle 24 is secured to the hub 20and serves to rotate the shaft I9, the shaft I9 being provided adjacentthe point of contact by the lower end of the vertical shaft I5 with acam portion 25, the cam portion being adapted to raise the shaft I5 whenthe handle 24 is operated to rotate shaft I9, and subsequently will liftthe table 8 off the pins I2 as indicated in dotted outline in Fig. 6,permitting the table to be swung to one side about the axis of the shaftI5 to a position as shown in Fig. 3. The vertical shaft I5 is providedwith a longitudinal bore 26 to permit the cam portion 25 of the shaft I9to be lubricated, thus assuring easy operation of the device, and thetable 8 is provided at the corner diagonally across from the shaft I 5with a short extension or handle portion 21 to be grasped by theoperator for ease in moving the table.

The table 8 has rotatably mounted on the upper surface thereof a discmember 28 having a centrally located vertical opening 29 in which isfixedly secured a translucent member 36, the opening 29 being invertical alignment with concentric openings 3! and 32 in the table 8 andbase I respectively. Thus, light emanating from a source such as bulb 33suitably located in the base I such as by socket 34 and bracket 35 canbe seen through the translucent light diffusing member 30 (Fig. 2), thelight being energized by any suitable source of current.

retaining :ring F36 iiis isecured to the iu'pper -isuri'ia.ce of lithetable :18 by means such as screws 31; the 'discla-being ot-such diameteras' tos'nugly reside within the o eriin in the ring 38 and rztateither'ein. Fixedly secured to the i upper surlace-of the disc '28 is abevel'ed ring member =38 hai ing a groove -O1-"Ghah nE-1 39 (Fi-gfi8)formed in the periphery thereof, the membermi being re *movably mountedon the m by means oflpi-ns ll, thetp'ins ll -being fixedly inouhted inthe dish 7 28 and zadaptea to co-i'nate with-Vertical o enings 1111 theunder side 'of the member :38. "Thus the member 3B:may be liftedofithe-pins 4il a i'iigl disc "28 :but in 'normaloperation is =-adapted tsreside against the surface "of menisc -'28 t be ror tated therewith. Theupper sur fa'ce ff-thedisb 28 is provided with a knu'r led por ton iZWhereby the {disc 28 and member 38 'm' eea'sily rotated. 'Ihe -mernber*38 is :prov-ided with vertieal 'ope'h ings-"AB which are' locatedadjacent tlie oi tei' edge or the -member 38 m sueh- 'a man er that thechannel 39 cuts into the side walls of the openings '40 to provide apassageway into said openings. --Prism regulating pins 4 3 ofvarying'lengths-are adapted to be inserted into the openings 40. Thepins are provided with a circumferential groove 44 in which a circularspring clip=or ring *45,-po- 's itionedin the channel 39, is adapted toremov- 'ably retain the pins in'theo'penings. Thus, the pins 45 may belifted'upwardly againstthe tension exerted by the clip or ring 45 to bereplaced or the like, with the replacement pin inserted into the openingAll and forced downwardly .against the-pressure 'exerted'byfthe clip orring 45 to become firmly seated in'a manner asshow'n 'inFig. 8. Theupperend of ea'chpin'43 is conically shaped as at 46, the apexthereof havinga short upward extension or ball portion 41, a lens *blank to beblockedbeing adapted to be rested upon the portions 41 of the pins.

"The disc 28 isprovided with a'plurality 0e10- cation lines dBwhichcooperatively function with a degree scale 49 marked on the-retaininring 2'36. The amount of the prism which is to beintroduced in the lensblank 50, which lens blank isbeing supportedby the ends of 'thepins 43,is determined by positioning pins E3 of the desired :controlled lengthsinthe openings 43in themem- =ber 38. By inserting pinsof varyinglengthsit will be seen that the lens blank 5!! will repose at varyingangles, and by .this means various amounts of prism'may be introduced inthelen's. The location lines 48 and degree scale 49 are for the purposeof locating the blank in the proper meridian according to'thefcylinderaxis'or pri'siin axisdesired in the finished lens. 'The'c'enter and theaxis lines are previously marked on the lens *blank following the-usualprocedure in-th'e manufacture of ophthalmic lenses, and areused to ac-Tcurately position the lens blank in=the present "device. In this mannerthe axis of theprism and :cylinder maybepositively located and theextent of prism may be 'introduced'as well as ac- -curate centering.

' After the lens blank'has been positioned, as I stated-above, aplurality ofcontact members 5| are moved directly into engagement withthe upper surface of the lens blank 50. The'contact :members 5|, asshown inFig-Z, are independently urged toward the lensblank EObymeansofback-' ting springsSZ which engage each of the contact [members 5|, atone end thereof, as indicated at j5,3,'and at the'op'posite ends engage'avsplitwasher 54. The washer 54 is formed ofitw'o semi-circularsha'p'e'd members which are adapteditobe located inacirrumrerentiargrotve in the"si"g'hting de- -v ibe body member t5 bymam ot a, 'siiil ihg-clip ot-wire 56, the upper-landed: the baekingsprings 52 being adapted 1 to engage i the lower surface 0f ithew-ashe'r 54. Ih'e boiiy membe-r '55 of the sighting device is ve itically movable internally or a housing ss 'earrieu byfthelsupporting-br aoket 5 and is provided "with a plliifi't y 01'Idhgitudifll g lodi es l as ShbWh' ih Fig. 2. "The Ebritiiliflm'lnbers5| and backing springs 52 are positioned within these grooves 5'! withsu'fiieien't clearance -so' that the body 'meinber 55 and attacheapartsarer-teem r'eciprocateasa un-it in the housing e il. I'he longitudinalgrooves 51 terminate i'n "shoul- "dered-edg'esSH and com-municate wi-thaplurality of openings in which the=reduced portions of the contactmember's 5| are sl-idabiy mounted. r-he members s! tareeae'hiprovi'de'dwithasnourtiered. portion' li I 1 which is adapted toengage the shouldered e'd'ge 59 6f the "grooves 51 and limit thedownwerd Iri'ov'ein ent srsma members 5| un- "der the reaction 'of' thebacking 'springs'fl. The "lower end ofthe body member 55 is prov'id'edwith a plurality of transversely-extendingopeningsElla direc tl-yintercepting the openings '6'!) in tvhihthe reduced-portions of thecontact members 51 are slidably mounted. Each of said latter-openings isadapted to receive tl'i'eshan-k offa knurled clamp screw 62; the *endsof the "shank being *adapted to directly or indirectly engagethecontact*mem=- leers 51 when the clamp screws 62 "are operated 'by anysuitable methodwhich may "be used for lo'c'king the contact members-"51against longitu- 'dinal movement-inthe openings fill.

The clamp screws "6'2 are'a'lso indirectlycon- *nected by means notshown with '-'a plurality of =downward1y extending isprin'g finger's 63,which fingers are rigidly attached adjacenttheiruppei' ends to-a ringmember 6 4 pressed'o'rotherwise {fixedlysecured about th'e body member55 near the lower end thereof-and'havetheir lower-ends {provided withmeans suchas heatr'esistantj rubber tribingor other"suitable"meansforming cushion grips Semiengaging theedgeo'f and-for gripping thelensblank 50. "The-clampscrewsfl and spring finge'rs "63 are constructed'and function in the 'sa'me manner as shown Patent -No. 2,253,954fi'ssued August 26, -194'-1,- to liloyd W. Goddu. It is "believedsufiicien't "to state that in the present invention a manually operable"handle 66 1(Fig. 1i protrudes fromthe casingii'l andis adapted to :bemoved tr'a'nSv'ersely-inja slotted opening in the "casingiil to rotate acam'me'chanism, which cam mechanism controls the inwardand outwardo'scihlati'ng movementofthespririg fihgers 63. When 'lthe clamp screws 62 areloosened the handle 66 may :be moved withinthe confine'srif the slottedo ening whereby thegrips 6"5fdfthespringfingers 63 are permitted toengagefthe edge of the lens blank '50, ripping the said ibl'ank throughthe "inherent *resiliencybf thefingers and "are held in grippingrelation with "the Ledge 'jof the blank tightening the clamp screws62,whie"h tightening "operationsimultaneously locksthe'jcontactmembe'r's 5| against "longitudinal movement in the I Thebodym'ember 55tisprovidedfas .showni'n iliig. 2 with a hollow bore inwhich is 'fxtended la sighting tube 68. This tube is secured to Ia eapmember69 andha's ;a'washer {1B flocated adjacent 'theupp'er end thereof,ithe'washerfbeingiprovided with a restricted opening 11,! centrallythereof. The cap "member '69 is lsi'milai'fly I provided ;with Tarestricted opening 72 in axial alignment with the opening TI and has atapered portion 'n. internally ertnehousmesa, the taper off e'jportionfilbi'ri'g cally earns the cap member 69 in a direction inwardlyof the housing 58 and forces the flange portion I of said cap member 69into binding relation with the upper edge surface of the housing 58. Thelower end of the sighting tube 68 is provided with a transparent memberI6 in the form of a disc having cross-hairs (not shown) thereon.

toward the lens supporting table 8. A rack sup porting lug TI is boltedor otherwise secured to the body member at a point well below the lowerend of the housing 53 and has connected thereto by screws I8 the lowerend of a vertically extending toothed rack I9, the rack being slidablydisposed through an opening in a boss 88 formed integral with the rearof the housing 53. A pinion gear 8| adapted to mesh with the rack I9 isfixedly secured to a shaft 82, the shaft being rotatably mounted in thebracket 6 and having an operating knob 83 secured to one end thereof.Thus, manual rotation of the knob 83 will cause vertical movement of thebody member 55 and consequently of the contact members 5| and springfingers 63, toward or away from the lens blank 58.

Means may be provided for holding the sighting device in its raisedposition. Such a device is illustrated in Fig. 13 and includes a coilspring [21 which is located in a transverse bore I28 in the supportingbracket 6 and is adapted to urge a ball member I29 positioned adjacentits outer end toward the rack I9. The bore I28 is threaded near itsouter end for reception of a threaded stud I38, which stud serves toretain the spring within the bore I28. A small cavity or indentation I3Iis formed in the side wall of the rack I9 where it may be engaged by theball member I29 of the spring detent when the sighting device is in itsraised position. When the ball member I29 engages the cavity |3I theaction of the coil spring I21 will maintain the sighting device in itsraised position. The sighting device may, however, be

lowered by rotating the knob 83 to overcome the force exerted by thespring I21. Suitable means such as a coil spring connected to thesighting device and the bracket 6 may be used if desired to control orcounterbalance the gravitational forces acting upon the sighting device.

In using this portion of the subject invention, the handle 66 isinitially moved to spread the spring fingers 63 outwardly- The knob '83is then manually rotated to lower the sleeve 51, and the contact members5| are guided into engagement with the upper surface of the lens blank58' positioned on the pin members 46. The said blank has been previouslyaligned as to center, its prism and cylinder axes, and the extent ofprism, and during the locating of the contact members 5| said blank ispreferably manually supported in desired aligned position on the pinmembers 46. The spring fingers 63 arenow operated so that they will gripthe contour edge of the lens blank 50. This is accomplished by movingthe handle 66 to permit the spring fingers to resiliently engage theedge of the lens blank with the contact mem- A check is then made bysighting through...the sighting tube 68 to insure that the lens blankhas not moved from its desired prelocated position. The clamp screws 62are then tightened to simultaneously secure the spring fingers 63 ingripping relation with the edge of the lens blank 50 and to secure thecontact members 5| against longitudinal movement. It is to be noted thatthe gripping ends 65 of the fingers 63 are angled inwardly so as toinsure a positive grip with the edge of the lens blank. After positivelylocating the spring fingers 63 and contact members 5| by tightening theclamp screws 62 the knob 83 may beagain rotated to raise the body member55 and consequently lift the lens blank 58 off the pins 46.

After removing the lens 50 from the pin members 46 the machine operatorwill rotate the handle 24 to raise the table 8, as hereinbeforedescribed. and by grasping the short extension 21 will swing the tableon the axis of the vertical shaft I5 to a sidewise positionsubstantially as shown in Fig. 3.

Located by bolts 84 on the base in axial alignment with the sightingdevice is an upright which has a tapering support 85 thereon on which isfitted an adapter 8'! holding a lens block 88. The upright is formedwith a base portion I32 on which resides a ring member 85 which isadapted to rotate about the tapered support 86. A vertical locating pinI33 is fixedly positioned in the upper surface of the ring member 85 andis adapted to engage a slot I34 in the adapter 8'1. Thus by rotating thering member 85 and pin I33 the adapter 8'! may be located as desired,set screws I35 being provided to lock the ring member 85 in adjustedposition. The adapter 81 has a recessed upper end (Fig. '7) in which isextended a shank 89 on the under side of the block 88, the shank 89having a circumferential taper 69 which is adapted to be'engaged by aplurality of set screws 9|. The tapered portion 99 is such that thebinding action of the set screws 9I moves the block 88 in a direction inwardly of the recess. The adapter 8! also has a tapered recess in itslower surface whereby it. may be easily positioned on the taperedportion 86 of the upright in axial alignment with the disc member 28 andsighting device. It is to be understood that the upright may bepermanently attached to the machine and is provided with a centralopening axially aligned with the sighting tube 68 and openings 32 and 3|in the base I and table 8 respectively, the adapter 8! to be attachedafter removal of the table 8 from position directly above the upright.

A vertical opening in the rear portion of the support 2 carries a shaft92 (Fig. 4), the opening being of such size as to rotatably receive theshaft 92 and having an opening of smaller diameter extending from thelower end thereof adapted to receive an extension 93 on the lower end ofthe shaft 92. The extension 93 of the shaft 8'2 has secured thereto by apin or other suitable means a collar 94 carrying an eccentricallylocated stud 95, the stud 95 being adapted to engage a leaf spring 95.The leaf spring 95 is the actuating member of a micro-switch 91, whichswitch is secured to the base I by means such as screws 98, and isadapted to be contacted by the stud 85 to open and close the switch 91upon rotation of the shaft 92. The switch 91 is adapted to control theenergic condition .of a heating element 98 fixedly mounted on therotatable shaft 92 adjacent the upper end thereof. Terminals I99 areprovided in the non;-

i l of the'arm II8 from engagement with the actuating member I I! whenthe unit is moved to operative position between the lens blank and lensblock allows the switch IIB- to close and thereby permits the heatingelement I I9 to become heated as in the preferred construction.

The upright 85 forsupporting the lens block adapter 81 is provided witha vertical opening I20 (Fig. 2) axially aligned With the base opening 32and table opening 3! to permit illumination from lamp 33 to passupwardly through the translucent light diffusing member 36 and toilluminate the lens blank 50. The lamp 33 is controlled by any suitableswitch arrangement and may be positioned slightly out of alignment withthe opening 32 and the member 30 for the purpose of providing indirectdiffused light or may be directly in alignment therewith in order toprovide the greatest illumination on the lens blank 50. If desired,suitable means may be provided for moving the lamp 33 into and out ofalignment.

It is to be understood that the movable lens supporting table 8 may beprovided with simple adjustable means for aligning the bushings I3 inthe under side thereof with the pins I2 when returning the table 8 toits position in spanning relation to the supports 2 and 3 after a lenshas been blocked and removed from the adapter 81,

whereby the table 8 may be more quickly and' easily positioned in axialalignment with the holding device for successive lens aligningoperations. This may be accomplished by providing means such as theadjustable stop member I2I located in the rear edge of the table member8 and adjustably positioned so that when the table 8 is swung to aposition spanning the supports 2 and 3 it will abut the front surface ofthe upright 4 to position the table forproper disposition thereof uponthe locking pins I2 without unnecessary feeling or groping. Also, ifdesired, the mechanism for raising and lowering the lens supportingtable 8 may be provided with a spring detent device for restraining thetable from undesired vertical movement. Such a detent similar to thespring detent of the sighting device is illustrated in Fig. 6 wherein acoil spring I36 and ball member I31 cooperate with cavities orindentations I38 in the transverse shaft I9, the spring and ball beingpositioned in a vertical bore I39 in the base I and retained therein bya stud I40. Thus the shaft I9 may be rotated to raise or lower the table8 and the detent will operate to maintain the table in either itsuppermost or lower position until enough manual force is applied to thehandle 24 to overcome the action of the spring I36 and thus permit thetable to be moved vertically.

Although the heating unit has been described as being energized whenmoved to a position in- I termediate the block and supported lens blank,the heating unit may, if desired, be in the form of a ceramic elementmovable into and out of operative position in a manner similar to theheating unit illustrated in Fig. 3. In this instance, the heating unitcould be located internally of the upright 4 and adapted to preheat orcontinuously heat the ceramic element so that when said element is movedin between the blank and block to heat the same, it will be preheated tothe required temperature.

- It is also to be understood that the table 8 may be provided with abase portion having a tapered bore adapted to fit over the taperedupright 86 for positional purposes and may be used either with orwithout the contact members 9 and I0.

' From the foregoing description it will be seen that an invention ofthe character described is very definitely animprovement over the priorart by providing a machine with improved means for sighting and grippingsemi-finished lens blanks for introducing desired opticalcharacteristics which the finished lens is to possess, and the lensblank held by the improved gripping means in such a manner as to retainits position with respect to the prescriptive characteristics; also byproviding neat and efiicient means for securing a lens blank to a lensblock by including a movable heating element adapted to heat theadjacent surfaces of the lens blank and lens block and insertion of anadhesive in the form of a solid of controlled size whereby the blank andblock may be joined in a very satisfactory manner, in contrast to themessy means employed by prior art devices which are generally of asomewhat involved nature and which employ a pot carrying a moltenadhesive and accessories necessary to confine the pitch to certain areasof the lens block to which the lens blank is to be attached. The presentinvention also improves upon the prior art by providing means forraising and lowering the lens blank in a vertical line of movementperpendicular to the surface of the table used for initially supportingthe lens blank and by shortening the length of travel and confining themovement thereof during the blocking operation to said vertical linethereby eliminating to a great degree possible inaccuracies in blocking.

The advantages of our invention will be readily understood from theforegoing description and, while we have shown and described a preferredembodiment of our invention, it is evident that various modificationsmay be made that will come within the scope of the invention, and we donot desire, therefore, to limit ourselves to the exact form ofconstruction shown and described herein.

Having described our invention, we claim:

1. In a device of the character described, the

, combination of a base, a holding device supported on said base, atable carried by said base having means for adjusting a lens blank to apredetermined position, said table being movable into and out ofalignment with the holding device, said holding device having grippingmeans adapted to contact and retain said lens blank in adjusted positionand being adapted to move said gripping means and said lens blank in adirection vertically toward or away from the plane of the table, lensblock supporting means on said base in axial alignment with said holdingdevice and adapted to support a lens block, and a heating device movablymounted on said base for movement in a direction transversely of theholding device and lens block supportin means into and out of positiontherebetween and being adapted to heat the adjacent surfaces of the lensblank and lens block when held by the respective holding device andsupporting means.

2. In a device of the character described, the combination of a base, atable member adjustably mounted on said base for movement between a pairof stations and carrying contacts on which a lens blank is adapted toadjustably reside in a predetermined position, a holding devicesupported on said base in axial alignment with one of said stations andmovable in a direction perpendicular to the direction in whichsaid tablemember is adapted to be moved, said holdin device having? erippmameansada t to contact andretaimsaidrlensiblank in adjusted. position: andbeing adapted: to; move; said. grip ping. means-1 and. said; lens blankin a. direction vertically toward.;.on away. from..said.:station-;..lens block supporting;- means: on said: base inaxial. alignment! with :said holding deviceandadapted to support; a:lens block. a heating; device, adj list--- ablv mounted=on. said base.-andadapted to. herm'ovedtintoi and tout of.- operativexposition between.the blankand. the lens; block anditd heatthe adj acenta surfaces.thereofi.

3LIn adeviceof the. character described, the: combination of; a,basehaving: support thereon: providedtw-ith-U a: member. carrying:contacts. on

which alens blank: is, adapted. to reside, said...

member. and--. said. contacts being. adjustable-;- to. locate-a the lensblanlc a. predetermined... posi. tion; aholding device: supported on:said base im. axial alignment with said. member carrying;- contacts. andmovable in: a direction toward and; away? from said support. saidholding-,- device haw ing. gripping, means adapted. to contact and-.161"taimsaid: lens blank in adjusted-positions and being adapted. to; move.said: gripping. means: and said. lensrblank: in a directionverticallytoward: on awa tfirom the membercarrying contacts, lensrbloclnsumwttingmeansicn said-.basein axe ialalignment with said: holding;device and; adaptedto. support alens. block, a. heating? dc. vice;ado'nstably mounted: on. said; base and? adapted to be: moved: in. adirections. transverselit oi-.the= lens-.-bloclr. supporting; means andholctj-.= ing device into and out of operative positiombee tweemthe.holding device and-thewlens block supporting means to heat-the;-adjacent isuriacesof the lens. blank ands lens.- bloek when: assembled?with... said holding; device: and; supporting. :mzeans:

4. I-ne alder ice. of the-character: described, the combination-ob abase; a tablevmember mounted on; said; base. said. table: members beingprovi-dedwithl a: member: carrying adjustablesspaceds. contactsonawhichi a lens blankz is adaptedatbi reside said: member being;adjustable to: locate;

the. lens blank. in accordance: withtits predator mined; cylinder axis,said contacts; being :adjustrabIecta provide: angular; displacement";of. the: lens blank to introduce a: predetermined amount 0t: prism.,thereto a holding. device supported; om said base. inaxial alignmentabove; said. tablemember: and movable in a. direction perpendic*---ul-an to the. surface of said; table member; said hold-mg; device:having. gripping means adapted}. to contact and retain said lensbl'anlein'adjusted" position and being adapted to move said gripping means andsaid lens blank: maydirection mommy toward" or" awayfrom. the tablemember; lens block" supporting means on, said base. in axial alignment.below said table. member and said holding; device. and adapted; to.supnortl alensblock, .a support. member pivotally. mounted on" saidbase. and. having. a' portion adapted}: to: be movedinto. and. out ofoperative positiombe tweentthe...lens .blankholding device andthez'lensrblock. supporting-1 means, said portion having: meansthereomtoheat the. adjacent surfaces: of a. supported lens blanklensblock, and an' adhesivememben adapted to be" applied to the heated.surface of; said lens block' supported in said means whereuponthezrliolding 'i device may be moved toward the. lens block: to bringthe supported lens.- blank into: engagement with" the; l'ens'block thehes-trot theel'ens blank-and the lens bloclc acting; upon. the 1adhesive member" to:

14 secureaztheslens; blankttopthe 1ens,block .while;.-the: blanks.isretained in: adjusted. position.

5... a device; of; the character; described. the.

combination 015: a. base-1; having spaced supports;

\ thereonwaitable member. mounted for. movement intoz andouhohapositionin spanning relation to said, supports, said table.member. having a rotatable-disc; member. located on the'top suriaeethereof]; carrying a; plurality. of, individually adjustable spacedcontacts on. which a lens blank ma'cementottha lens-blank .to introducea;.pre.-

determined. amount. of prism thereto, controlline mechanism. for.locating; said table; member. in. said position comprising, pluralityof: pin. members located insaid. supports and adapted to; col-mate;with. openings. formed in the. lower: surface. of said... table. member,and. manually operable... lifting. means. for. raising said tablefromsaid; pin. members to, permit the. table to.

be..moved fromsaid' position spanning the supnonts, a holding devicesupported on. said base: int axial. alignment with} said, table whensaid: table. locatedtby. said. p-instr in said position; said" holding,device... having; gripping means adantedfiocontactlthe.peripheral edges.of a lens blankand releasably retain; said lens blank; in. adjusted.nositiomand. being adapted. to. move; sjaidfi gripping means and, saidretained. lens. blank; iniat direction. vertically toward; or away from.the. spaced supponts,,, lens. block.- supporting,meansaon;.said}base in.axial. alignment with. said holding device. and adaptedto-support a lensblookti'n alignment with the. lensblank, a heating, device mounted'onsaidbase. and having a, portion. adapteditobe. moved intomandout of.operative; position between the holding deviceion lensblank;

and the lensblocksupporting means-,.said portion Having. means. for.heating the adjacent surfaces of the lens. blank. andlblock wherebyanadhe-- site may. be applied. tov the heated surface?" at" said! lens.block. and. the. holding device moved downwardly totb'ring. thelensrblank into engagementiwithsaidi adhesive. on the 1 block, the heat.off'tlie; lens. blank and the. lens block acting; upon the. adhesive to.secure. the 18I1S-b18fnkw to the lens blocliwh'ile the lens blankisretained; in its. adjustedl. position, by the, gripping means ofthel'ioldiiigidevice, said gripping means be ing releasable to. permit.removalkof the lens block. ancf'lenszblankadhesively secured thereto.inde siredj adiiisted relation...

6."; In a: devicepoffithe. character. described, the combinationofiabase, a tablelmember' located. on" saictibase carryingspacedcontacts on which a lens blanlt adapted toiadjustably residein;

a predeterminedposition, sighting; means suppoetedomsaidlbase ineaxialalignment with said table. member. togethenwith target means. foraligning, the; optical axis .Jt-he; lensrblank therewith; a. holdingdevi'cevhaving: gripping means adaptedto contact and retainzsaid lensblank when. im adjusted: position, means for" moving saidholdingdevicewin a direction vertically to-' or. awayfrom the adjusting means,lens hloclc'sapporting meanston said base in axial alignment: witlr isaid ltarget means and sighting meansand' adapted to'support lens block,a heating device mounted: on said base and hava portion movable indirections transversely. of the' lns 'blbck supporting" means and.hold"- i 'ng deviceinto" and out" of operative position portion havingmeans to heat the adjacent surfaces of the lens blank and lens'blockwhereby an adhesive may be applied tothe heated surface of said lensblock and said lens blank may be moved by the holding device intoengagement therewith, the heat of the lens blank and the lens blockacting upon the adhesive to secure the lens blank to the lens blockwhile the lens blank is retained in adjusted position, and said grippingmeans being releasable to permit removal of the lens block with the lensblank adhered thereto.

7. In a device of the character described, the combination of a base,adjusting means on said base for supporting a lens blank in apredetermined position, a holding device supported on said base havinggripping means adapted to contact and retain said lens blank in aposition to which it has been adjusted and being adapted to move saidgripping means and said retained lens blank in a direction toward oraway from the adjusting means, lens block supporting means on said basein axial alignment with said holding device and adapted to support alens block, a shaft rotatably mounted on said base, a support adapted tobe moved by rotation of said shaft into and out of operative positionbetween the holding device and the lens block supporting means, saidsupport having a heating element adapted to be energized by suitableelectric current, and a switch located in a position to be contactedupon rotation of said shaft, whereby upon movement of the support intoope erative position between the holding device, and lens blocksupporting means said switch will cause said heating element to beenergized and upon movement of said support out of operative positionsaid switch will deenergize said heating element.

8. In a device of the character described, the combination of a base,adjusting means onsaid base for adjusting a lens blank to apredetermined position, a holding device supported on said base havinggripping means adapted to contact and retain said lens blank when in anadjusted position and being adapted to move said gripping means and saidretained lens blank in a direction toward or away from the adjustingmeans, lens block supporting means on said base in axial alignment withsaid adjusting means and said holding device and adapted to support alens block, a heating device adapted to be moved into and out ofoperative position between the lens blank and the lens block and to heatthe adjacent surfaces thereof, said device embodying a heating elementhaving coils adapted to be energized by suitable electric current, areflector located on the heating element to be between the element andsaid lens blank when the device is in said operative position and havingmeans associated therewith for controlling the heat projected upon thelens blank and for reflecting an additional amount of heat to said lensblock, and a rotatable shaft supporting said heating device upon saidbase, said shaft being rotatable to move the heating device into and outof said operative position, and a switch located in a position to becontacted upon rotation of said shaft, whereby upon movement of theheating device into operative position between the holding device andlens block s'upporting'means said switch will be contacted to cause saidheating element to be energized and movement of said deviceoutofoperative position will operate to release said switch to tie-energizesaid heating element.

9. In a device of the character described, the combination of a basehaving adjusting means on which a lens blank is adapted to adjustablyreside in a predetermined position, a holding de-,

vice supported on said base in axial alignment with said adjustingmeans, said holding device having gripping means adapted to contact andretain said lens blank when in an adjusted position and being adapted tovertically move said gripping means and said lens blank in a directiontoward or away from the adjusting means. lens block supporting means onsaid base in axial alignment with said adjusting means and said holdingdevice and adapted to support a, removable lens block, a heating devicemounted on said base for movement in directions transversely of theholding device and lens block supporting means into and out of operativeposition between the lens blank and the lens block and having means toheat the adjacent surfaces of the lens blank and lens block whensupported,

and an adhesive in the form of a solid adapted to be applied to theheated surface of said lens block, and means for moving said holdingdevice to bring the heated surface of said lens blank into engagementwith the adhesive on the lens block while the lens blank is held inadjusted position so as to secure the blank to the block while retainedin said position, and said gripping means being releasable to permitremoval' of the lens block with the lens blank adhered thereto.

10'. In a device for locating a lens blank, the combination of a basehaving spaced supports thereon, atable member adapted to operativelyreside in spanning relation to said supports,

manually operable means for controlling the location of said tablemember comprising a sup porting shaft to which the table member isfixedly secured, said supporting shaft being rotatably mounted in one ofsaid supports, and an operating shaft adapted to control the verticalposition of said supporting shaft to raise or lower 11. In a lensblocking device, means for se-' curing a lens blank to a lens blockcomprise a solid pellet of heat softenable adhesive material, and abacking of coarse open-mesh-bonding material imbedded in a surfacethereof.

12. In a lens blocking device, means for securing a lens blank to a lensblock comprising a solid adhesive pellet of a substantially hard brittlenature when not subjected to heat, said adhesive having a coarseopen-mesh bonding material imbedded in a surface thereof and adapted,when said pellet is broken, to retain the pieces thereof insubstantially their original relations to one another, said pellet,including broken pieces thereof, being adapted to become molten and toflow into a single molten mass when subjected to heat.

- 13. A device of the character described comprising the combination ofmeans for adjustingand supporting a lens blank in a givenposition,meansfor supporting a lens block in alignment with said lens blank, oneof said supports being movable towards the other, heat generating meansmovable into and out of a station located between said supporting meansfor the lens blank and for said block for heating the adjacent surfacesof said blank and block when assembled therewith whereby an adhesive ofa controlled amount may be positioned between said blank and block so asto be softened by the heat of said blank and block, and means for movingsaid movable support so as to bring the blank and block into engagementwith the adhesive while retaining said blank in said adjusted andsupported position. a

14. In a lens blocking device, the combinatio of a lens block support, asupport for maintain ing a lens in alignment with said lens blocksupport, a table mounted for movement into and out of position between.the lens block support and the lens support, a ijusting means on saidtable for locating a lens in a given determinable relation to the lensblock to be supported in the lens block support, a heating element mov-"able into and out of a station located between the lens block supportand the lens support, and means for moving one of said supports towardand away from the other.

15. In a lens blocking device, a lens block support, means forsupporting a lens in alignment above said lens block support, said meansbeing adapted to move the lens in a direction toward and away from thelens block support, a table. mounted for movement into and out of astationlocated between the lens block support and the lens supportingmeans, adjusting means on said table for locating a lens in a givendeterminable relation to the lens block to be supported in the lensblock support, and a heating element mounted on the device and movableinto and out of said station located between the lens block' support andthe lens supporting means when the table is not at said station.

16. In a lens blocking device, the combination of a lens block support,a support for maintaining a lens in substantial alignment with said lensblock support, a table mounted for movement into and out of a stationlocated between the lens block support and the lens supporting means,adjusting means on said table for locating a lens in a givendeterminable relation to the lens block to be supported in the lensblock support, and means for moving one of said supports toward theother to bring the lens and lens block into adjacent relation.

17. In a lens blocking device, the combination of a lens block support,a support for maintaining a lens in substantial alignment with said lensblock support, adjusting means intermediate said lens clock support andthe lens support for locating a lens in a given determinable relation tothe lens block to be supported in the lens block support, and a heatingelement movable into and out of a station located between the lens blocksupport and the lens support.

18. In a lens blocking device, an adhesive member for securing a lensblank to a holder comprising a relatively thin, solid disc-like por tionof heat-effective adhesive, said adhesive being of a relatively brittlenature when cold and adapted to flow when heated, said disc having acoarse reinforcing member of open-meshed material impressed in a surfacethereof to maintain the portions of adhesive together when broken and toretard sidewise flow of the adhesive when heated.

DANIEL P. BERNHEIM. CARL G. SILVERBERG.

REFERENCES CITED The following references are of record in the fileofthis patent:

UNITED STATES PATENTS

